In a Microsoft Exchange Server 2016 environment, you use Outlook Web Access (OWA) to create a new category. If the name of the new category is the same as an existing one but has a different case sensitivity, the new category is not created.
This issue occurs because OWA does not validate case-sensitive for category.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Learn about the terminology that Microsoft uses to describe software updates.